Development of a preoperative nomogram for the prediction of non-biochemical recurrence rate after robot assisted radical prostatectomy in Japanese patients with clinically localized prostate cancer

[ABSTRACT] OBJECTIVE: To develop a preoperative nomogram to predict the non-biochemical recurrence (non-BCR) after robot-assisted radical prostatectomy (RARP). METHODS: A thousand patients who underwent robot-assisted radical prostatectomy at the Tokyo Medical University were studied. Based on Cox hazard regression analysis, a nomogram was developed to predict non-biochemical recurrence at 1, 3, and 5 years after robot-assisted radical prostatectomy. For external validation, the parameters of 200 patients who underwent robot-assisted radical prostatectomy at the Shin-Yurigaoka General Hospital were used to calibrate the actual and predicted values using our nomogram. RESULTS: A hundred and sixty-eight patients had biochemical recurrence during the follow-up period (mean, 44.4 months). Analysis showed that age, PSA, biopsy primary and secondary Gleason pattern, clinical T stage, and the percentage of positive biopsy cores were significant predictors of biochemical recurrence. CONCLUSION: The nomogram was validated with internal and external calibration to provide an accurate prediction of non-biochemical recurrence. It may help both patients and clinicians to determine the most appropriate initial treatment for clinically localized prostate cancer.